Vacuum controlled dampening device for secondary throttles



y 4, 1961 T. F. CRAMER 2,991,053

VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY THROTTLES Filed Sept.2, 1958 2. Sheets-Sheet 1 m o a} o N 0 Q- 9\ o m O O (I) (O Y q- LO 3 mu u INVENTOR.

THOMAS F. GRAMER ATTORNEYS July 4, 1961 -r. F. CRAMER 2,991,053

VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY THROTTLES Filed Sept.2, 1958 2 Sheets-Sheet 2 4 62 6o 58 FIG.2. I72

7: 9 o 54 070 Q o 30 v 64 I64 56 o o 52 I68 38 o 7 I24 5 (6;

I J FIG.5.

j INVENTOR.

THOMAS F.CRAMER BY w m 441/ ATTORNEYS United States Patent() 2 991 053VACUUM CONTROLLED DAMPENING DEVICE FOR SECONDARY TI-IRO'ITLES Thomas F.Cramer, Warren, Mich., assignor to Holley Carburetor Company, Van Dyke,Mich., a corporation of Michigan Filed Sept. 2, '1958, Ser. No. 758,207

Claims. (Cl. 261-23) This invention pertains to a selective dampeningdevice and more particularly to a dampening device for use with asecondary throttle plate in an internal combustion engine multiple stagecarburetion system.

A multiple stage carburetion system comprises an operator-controlledprimary throttle plate assembly and a venturi vacuum controlledsecondary throttle plate assembly which is operable to supply additionalair flow to the combustion chambers at high speeds.

a In engines having governing systems wherein at govapplying a dampeningor resisting movement to the secondary plate so that its initial closingafter governing is modified and subsequent changing of the primarythrottle plate is substantially eliminated.

The dampening action is provided by a piston which is operated in aclosed cylinder with restrictions formed in the piston walls to providelimited fluid movement therethrough resulting in a controlled pistonmovement. The piston is connected to the secondary throttle plate andthe cylinder has a lost motion connection to an en-.gine-vacuum-responsive rod. Placed intermediately of the cylinder andthe lost motion connection is a fork which is registrable with a lockattached to the carburetor body and under the proper vacuum conditions,the vacuum-responsive rod is moved against spring pressureto engage thefork with the lock so that any subsequent movement of the secondarythrottle will be subject to the controlled movement of the piston in thecylinder, thereby dampening the quick secondary plate movement andpreventing hunting.

It is therefore an object of this invention to provide in a governed,multiple-stage carburetion system means for eliminating the huntingwhich occurs at governed speeds.

Another object is to provide the secondary throttle plate assembly insuch a system with dampening means which is selectively applied toprevent exceptionally quick plate movement and subsequent hunting of thesecondary throttle plate.

A further object is to provide in a governed multiplestage carburetionsystem dampening means for the secondary throttle plate in the form of apiston and cylinder combination with the piston being connected to thesecondary throttle plate and with the cylinder having a lost motionconnection to an engine vacuum responsive member so that due to the lostmotion connection the secondary throttle movement is unmodified and withlockingmeans to lock the cylinder against the carburetor body toeifect-ively eliminate the lost motion connection so that the secondarythrottle plate is subject to the controlled movement of the piston inthe cylinder.

taken in conjunction with the accompanying drawings,

FIG. 1 is a side elevational view with portions thereof in cross sectionof a four-barrel carburetor provided with a governor embodying theinvention;

FIG. 2 is a side elevational view, with portions thereof in crosssection, taken on the plane of line 2-4v of FIG. 1 and looking in thedirection of the arrows;

FIG. 3 is a bottom plan view taken on the plane of line 3-*3 of FIG. 1and looking in the direction of the arrows;

FIG. 4 is a sectional view taken along the line 4-4 of FIG. 3;

FIG. 5 is a view taken from the direction of arrow 5 in FIG. 4 showingthe carburetor body attached lock.

Referring now to FIG. 1, a four-barrel carburetor 10, of the typereferred to above and having an air intake 12, is sectioned to exposeone of the primary barrels 14 and one of the secondary barrels 16. Theprimary barrel 14 is provided with a restriction or venturi throat 18and a conventionally operated throttle plate 20 mounted on the shaft 22which extends through the other primary barrel in which is mounted athrottle plate identical to plate 20. The secondary barrel 16 is alsoprovided with a venturi throat 24 and a throttle plate 26 mounted on theshaft 28 which extends through the other secondary barrel in which ismounted another secondary plate.

While a particular four-barrel carburetor is shown for purposes ofillustration, it will be apparent that the invention is equallyapplicable to two-barrel or other multistage carburetors.

-A vacuum device 30, commonly referred to as a governor diaphragmassembly, is mounted on the boss 32 extending from the carburetorthrottle body 34. The

.36 by means of a cover member 44 formed to provide an air tight chamber46 of which the flexible diaphragm 42 forms a wall. The cover member maybe secured by any suitable means such as screws 47.

-As shown by FIGS. 1 and 2, the diaphragm 42 has secured to the centerthereof in the conventional manner a rod 48 passing through passage 50in the body 36 and having a. laterally extending end 52 pivotallysecured to the lever 54 which is rigidly secured to the end 56 of theprimary throttle shaft 22 extending into the chamber 38. The shaft 22 ismounted in an anti-friction bearing 39, and a spring 41 is disposedbetween the bearing 39 and the steel and leather washers 43 and 45 toprovide a seal. A tension spring 58 attached between the adjustable pin60, mounted in one of the holes 62 in the body 36, and

the fixed pin 64, secured to the lever 54, tends to hold the primarythrottle plate 20 in the open position. An atmospherically vented coverplate 66 may be secured by screws 68 to housing 36, thereby protectingthe mechanism within chamber 38.

The orifice 72 at the primary venturi throat 18 and the orifice 74 belowthe primary throttle plate 20 are connected by means of the passages 76and 78 having :fixed restrictions 80 and 82 respectively with thepassage 84 in the :body member 36 and the passage 86 in the cover member44 which lead to the chamber 46. A passage 88 connecting with passage 84terminates in an opening in 102 in the sleeve by attachment at one endto the internally threaded member 104, which is keyed in passage 102.Spring 100 is adjustable axially of sleeve 98 by turning the adjustmentscrew v106 which is reached by removing the access screw 108. The otherend of the spring 100 is secured to the governor weight 110 movableaxially within the chamber 112 against the spring 100 and having at thefree end thereof a valve 114 adapted to close the orifice .116 when theweight 110 is forced outwardly due to the rotation of the shaft 96 andthe sleeve 98 in accordance with engine speed. The engine or vehiclespeed at which the orifice 116 will be closed is dependent, of course,upon the adjustment of the spring 100. It is apparent, also, that someother governor valve structure may be employed.

A vacuum balancing air bleed is provided through assembly 92 to chamber46 when orifice 116 is uncovered. Conduit 118 between the air intake 12of the carburetor and the housing 94 and conduit 122 between the housing94 and the passage 88 in the body 36 are provided so that when theengine or vehicle is operating at a speed insufiicient to close theorifice 116, engine vacuum will draw clean air through the conduit 118,into the housing 94, through the orifice 116 and into the chamber 112,through the passage 102 and the axial passage 120 in the shaft 96 andthence through the condui-t 122 to the governor diaphragm assembly 30.When the engine reaches governed speed, the orifice 116 is closed andthe air bleed through conduit 122 is cut off. When this occurs, vacuumin the chamber 46 urges the diaphragm 42 downwardly, as in FIG. 2,against the spring 58 to close the primary throttle plates 20.

A secondary throttle diaphragm assembly 124 is mounted at the oppositeside of the throttle body 34. This assembly comprises a body 126 havinga recess 128 vented to the atmosphere through a plate 130 secured byscrew 132 and a recess 134 closed by a flexible diaphragm 136 which issecured to the body 126 by means of a cover 138 formed to provideoppositely disposed chambers 140 and 142 between which the flexiblediaphragm 136 forms a movable wall. The chamber 142 contains acompression spring 144 positioned between the cover V138 and the rod146, which is secured to the center of the diaphragm 136, so that thespring 144 urges the rod 146 upwardly to rotate the lever 148 securedrigidly to the secondary throttle shaft 28 counterclockwise, as in FIG.3, and close the secondary throttle plates 26. A conduit 150 extendingbetween the chamber 142 and the vacuum passages 152 and 154 opening tothe primary and secondary venturi throats 18 and 24 enables primaryand/or secondary venturi vacuum to evacuate the chamber 142 and displacethe diaphragm 136 downwardly, as in FIG. 1, against the spring 144 toopen the secondary throttle 26. The force of the spring 144 is selectedso that the secondary throttle plate 26 will be open at anypredetermined venturi vacuum.

The structure described above, or its equivalents, is well known in theart, and proper governing action depends upon the particular closing ofthe throttle plates 20 and 26 when the engine or vehicle has reached apredetermined governing speed so as to diminish or cut ofl? the flow ofmotive fluid to the engine. However, in the case of dual carburetion asdescribed above, the automatic closing of the secondary throttle plates26 lags behind that of the primary throttle plates 20, particularly atgoverned engine speeds at which the second plates 26 are not fully openso that linkage (not shown) usually effective to positively close thesecondary plates 26 with the primary plates 20 does not come intooperation. While this is tolerable in the normal function of the dualcarburetor, e.g., during acceleration, it is highly objectionable forthe purposes of governing. This causes hunting, since the primarythrottle plates have to first close farther than would otherwise berequired to com- 4 pensate for the open secondary plates and then openwhen the secondary plates finally close.

In order to remedy this situation a dampening device is provided asshown in FIGS. 3-5. Diaphragm assembly 156 is welded or otherwiseattached to diaphragm assembly 124 and has diaphragm 157circumferentially secured therein and urged by spring 158 to an upwardposition. Tube 159 communicates with a vacuum source such as enginemanifold vacuum or governor vacuum and lifts diaphragm 157 againstspring 158. Attached to and movable with diaphragm 157 is rod 161 havinga transversely extending pin 162 at the outer bifurcated end thereofwhich is engaged with slotted end 163 of threaded rod 164. Intermediateof the ends of rod 164 is fork 166 which is secured on either side bythreaded nuts and is engageable with carburetor body attached lock 167.The other end of rod 164 is attached to closed, oil filled cylinder 168having piston head 170 slidable therein. Formed along the walls ofpiston head 170 are longitudinal grooves 171 which permit limited flowof oil or other suitable fluid from one side of the piston head to theother opposing its movement and providing a dampening effect. Piston rod172 is pivotally connected to arm 148 as indicated at 149.

In the operation of this device as governing speed is approached, anincrease in the vacuum applied to the diaphragm 157 through tube 159causes the diaphragm and rod 161 to move downwardly engaging fork 166with lock 167. Any movement of secondary throttle lever 148 will nowcause movement of piston head 170 in cylinder .168 and since thismovement is restricted, movement of the secondary throttle will bedampened.

When the vacuum applied to diaphragm 157 is reduced, spring 158 willurge fork 166 to an unlocked position and movement of arm 148 will notbe dampened. A lost motion connection between rods 161 and 164 isprovided so that in the unlocked position, rod 161 will not interferewith the movement of rod 164.

While control of the application of dampening elfect in accordance withmanifold vacuum is satisfactory, it has been found that supplyinggovernor pressure from line 122 results in a very desirable responsemovement of diaphragm 157 since this pressure is not as sensitive toslight changes in engine speed. Of course, other suitable actuatingmeans for rod 161 may be used to properly and timely lock rod 164.

If desired, of course, all or any part of the structure shown herein maybe incorporated into a single, compact carburetor unit adapted forplacement in a vehicle engine compartment.

The drawings and the foregoing specification constitute a description ofthe improved vacuum controlled dampening device for secondary throttlesin such full, clear, concise and exact terms as to enable any personskilled in the art to practice the invention, the scope of which isindicated by the appended claims.

What I claim as my invention is:

l. A dampening device for an internal combustion engine comprising acarburetor having a barrel in which a throttle plate is pivotallysupported, actuating means for moving said throttle plate to variousthrottle plate positions in said barrel, dampening means engageable withsaid actuating means to dampen movement of said throttle plate, andselective means responsive to speed for operably connecting saiddampening means with said actuating means at a selected engine conditionwhich is also a function of speed to dampen throttle plate movement.

2. A dampening device for an internal combustion engine comprising acarburetor having a barrel in which a throttle plate is pivotallysupported, actuating means for moving said throttle plate to variousthrottle plate positions in said barrel, a double acting piston movablein a closed, fluid filled cylinder, a restricted fluid passage betweenopposite piston ends to provide controlled piston movement in bothdirections, and means for selectively applying said controlled pistonmovement to the throttle plate under a selected engine condition whichis a function of speed so that movement of the throttle plate isSubjected to a dampening action.

3. A dampening device for an internal combustion engine comprising amultiple stage carburetor having priand secondary barrels, a throttleplate pivotally mounted in. said secondary barrel, actuating means for'moving said throttle plate to various throttle plate positions in saidsecondary barrel, a piston movable in a closed, fluid filled cylinderand arestricted fluid passage being between opposite piston ends toprovide controlled piston movement, movable means responsive to aselected engine condition which is a function of speed, one of saidpiston and cylinder being connected to said actuating means and theother being connected through a lost motion connection to said movablemeans, and means for locking the other of said piston and cylinder whensaid movable means is actuated so that said actuating means is subjectto the dampened movement of said piston in said cylinder.

4. A dampening device for an internal combustion engine comprising amultiple stage carburetor having primary'and secondary barrels, athrottle plate pivotally mounted in said secondary barrel, actuatingmeans for moving said throttle plate to various throttle plate positionsin said secondary barrel, a piston movable in a closed, fluid filledcylinder, a restricted fluid passage be tween opposite piston ends toprovide controlled piston movement, engine governing means, movablemeans responsive to an engine governing condition which is a function ofspeed, one of said piston and cylinder being connected to said actuatingmeans and the other being pivotally connected through a lost motionpivot connection to said movablemeans, fonked means connected to theother of said piston and cylinder, and lock means registrable with saidforked means for relatively fixing the other of said piston andcylinder, said movable means being actuated upon the attainment of theengine governing condition which is a function of speed to urge saidforked means into engagement with said lock means so that said actuatingmeans is subject to the dampened movement of said piston in saidcylinder.

5. A dampening device for an internal combustion engine comprising acarburetor having a barrel in which a throttle plate is pivotallysupported, actuating means for moving said throttle plate to variousthrottle plate positions in said barrel, a piston movable in a closed,fluid filled cylinder, a restricted fluid passage between oppositepiston ends to provide controlled piston movement, engine vacuumresponsive means movable under a selected engine condition which is afunction of speed, one of said piston and cylinder being connected tosaid actuating means and the other being connected through a lost motionconnection to said engine vacuum responsive means, and means for lockingthe other of said piston and cylinder when said engine vacuum responsivemeans is moved so that said actuating means is subject to the dampenedmovement of said piston in said cylinder.

6. A dampening device for an internal combustion engine comprising acarburetor having a barrel in which a throttle plate is pivotallysupported, actuating means for moving said throttle plate to variousthrottle plate positions in said barrel, a piston movable in a closed,fluid filled cylinder and a restricted fluid passage between oppositepiston ends to provide controlled piston movement, locking means, one ofsaid piston and cylinder connected to said throttle plate, the otherconnected to said locking means, and means responsive to an enginevacuum condition for holding said locking means in a relatively fixedposition so that said throttle plate is subjected to the dampeningaction of said piston in said cylinder.

7. A multiple stage carburetor for an internal comnect and disconnectsaid dampening means to and from said secondary throttle.

8. Amultiple stage carburetor for an internal combustion enginecomprising primary and secondary barrels,

primary and secondary throttles located respectively in said barrels, aspeed governor for actuating said primary throttle, means responsive toan engine governing condition which is a function of engine load andspeed, said means being connected to said secondary throttle foractuating the same, dampening means effective to oppose movement of saidsecondary throttle, and dampening control means responsive to an enginegoverning condition which is a function of speed to operatively connectand disconnect said dampening means to and from said secondary throttle,said dampening means comprising a piston member, a closed fluid filledcylinder member in which said piston member is movable, fluid flowremeans connecting one of said members to said secondary throttle.

9,. A multiple stage carburetor for an internal com- "bustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively 'in said barrels, a speed governor foractuating said primary throttle, means responsive to an engine governingcondition which is a function of engine load and speed, said means beingconnected to said secondary throttle for actuating the same, dampeningmeans effective to oppose movement of said secondary throttle, anddampening control means to operatively connect and disconnect saiddampening means to and from said secondary throttle, said dampeningmeans comprising a piston member, a closed fluid filled cylinder memberin which said piston member is movable, fluid flow restricting passagemeans connecting opposite end portions of said cylinder to restrict flowin both directions, and means connecting one of said members to saidsecondary throttle, said dampening control means being responsive toengine manifold vacuum.

10. A multiple stage carburetor for an internal combustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively in said barrels, a speed governor foractuating said primary throttle, means responsive to an engine governingcondition which is a function of engine load and speed, said means beingconnected to said secondary throttle for actuating the same, dampeningmeans effective to oppose movement of said secondary throttle, anddampening control means to operatively connect and disconnect saiddampening means to and from said secondary throttle, said dampeningmeans comprising a piston member, a closed fluid filled cylinder memberin which said piston member is movable, fluid flow restricting passagemeans connecting opposite end portions of said cylinder to restrict flowin both directions, and means connecting one of said members to saidsecondary throttle, said control means being responsive jointly toengine manifold vacuum and venturi vacuum.

11. A multiple stage carburetor for an internal combustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively in said barrels, a speed governor foractuating said primary throttle, means responsive to an engine governingcondition which is a function of engine load and speed, said means beingconnected to said secondary throttle for actuating the same, dampeningmeans efiective to oppose movement of said secondary throttle dampeningcontrol means responsive to an engine governing condition which is afunction of speed to operatively connect and disconnect said dampeningmeans to and from said secondary throttle, said dampening meanscomprising a piston member, a closed fluid filled cylinder member inwhich said piston member is movable, fluid flow restricting passagemeans connecting opposite end portions of said cylinder to restrict flowin both directions, and means connecting one of said members to saidsecondary throttle, said dampening control means including meansoperably connected to the other of said members and means selectivelyeffective upon the attainment of the engine governing condition toprevent movement of said other member and thereby oppose movement ofsaid one member.

12. A multiple stage carburetor for an internal combustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively in said barrels, a speed governor foractuating said primary throttle, means responsive to air flow to theengine, controlled in part by the positions of both of said throttles,said means connected to said secondary throttle for actuating the same,dampening means effective to oppose movement of said secondary throttle,and dampening control means responsive to engine manifold vacuum tooperatively connect and disconnect said dampening means to and from saidsecondary throttle.

13. A multiple stage carburetor for an internal combustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively in said barrels, a speed governor foractuating said primary throttle, means responsive to air flow to theengine, controlled in part by the positions of both of said throttles,said means connected to said secondary throttle for actuating the same,dampening means effective to oppose movement of said secondary throttle,and dampening control means responsive jointly to manifold and venturivacuum to operatively connect and disconnect said dampening means to andfrom said secondary throttle.

14. A multiple stage oorburetor for an internal combustion enginecomprising primary and secondary barrels, primary and secondarythrottles located respectively in said barrels, a speed governor foractuating said primary throttle, means responsive to air flow to theengine, controlled in part by the positions of both of said throttles,said means connected to said secondary throttle for actuating the same,dampening means efiective to oppose movement of said secondary throttle,and dampening control means responsive to an engine governing conditionwhich is a function of speed to operatively connect and disconnect saiddampening means to and from said secondary throttle, said dampeningcontrol means including means operable only throughout a limited powerrange commencing at governor cut-oif.

15. A dampening device for an internal combustion engine comprising acarburetor having a throttle plate pivotally mounted therein, actuatingmeans for moving said throttle plate to various throttle platepositions, and dampening means connected to said throttle plate, saiddampening means being responsive to a selected engine condition which isa function of speed to selectively apply dampening action to themovement of the throttle plate.

References Cited in the file of this patent UNITED STATES PATENTS2,315,912 Udale Apr. 6, 1943 2,609,187 Scott Sept. 2, 1952 2,703,705Boller Mar. 8, 1955

